Blood transfusion is associated with increased morbidity and mortality after lower extremity revascularization

A Meta-Analysis to Derive Population-Based Quality Benchmarks of the Incidence of Surgical Site Infection after Lower Limb Revascularization Surgery

BACKGROUND

The reported incidence of surgical site infection (SSI) after lower limb revascularization surgery varies. We conducted a systematic review and meta-analysis of population-based studies reporting the incidence of SSI in adults who underwent these surgeries in high-income countries to derive SSI quality benchmarks.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception-to-April 28th, 2022) for population-based studies estimating the cumulative incidence of SSI among adults who underwent lower limb revascularization surgery for peripheral artery disease (PAD) in high-income countries. Two investigators independently screened abstracts and full-text articles, extracted data, and assessed risks of bias. We used random-effects models to pool data and GRADE to assess certainty.

RESULTS

Among 6,258 citations, we included 53 studies (n = 757,726 patients); 8 of which (n = 435,769 patients) reported nonoverlapping data that were meta-analyzed. The pooled cumulative incidence of any SSI was 6.0 in 100 patients [95% confidence interval (CI) = 4.3-8.0 in 100 patients; n = 8 studies; n = 435,769 patients; moderate certainty]. The cumulative incidence of Szilagyi grade I (cellulitis), grade II (subcutaneous tissue), and grade III (prosthetic graft) SSI was 6.5 in 100 patients (95% CI = 4.3-8.6 in 100 patients; n = 2 studies; n = 39,645 patients; low certainty), 2.1 in 100 patients (95% CI = 2.0-2.3 in 100 patients; n = 2 studies; low certainty), and 0.4 in 100 patients (95% CI = 0.4-0.4 in 100 patients; n = 1 study; n = 333,275 patients; low certainty), respectively. The pooled cumulative incidence of any early (in-hospital/≤30-days) and late (>30-days) SSI was 6.2 in 100 patients (95% CI = 4.4-8.0 in 100 patients; n = 7 studies; n = 431,273 patients; moderate certainty) and 3.7 in 100 patients (95% CI = 2.2-5.2 in 100 patients; n = 2 studies; n = 10,565 patients; low certainty), respectively.

CONCLUSIONS

This systematic review derived population-based benchmarks of the incidence of any SSI; Szilagyi I, II, and III SSI; and early and late SSI after lower limb revascularization surgery. These may be used by practicing surgeons and healthcare leaders/administrators to guide quality improvement efforts in the United States and perhaps other countries.

The effect of incremental increases in the number of packed red blood cell units transfused on perioperative outcomes in open abdominal aortic aneurysm repair

INTRODUCTION

Despite abundant evidence in the surgical and critical care literature demonstrating inferior outcomes in transfused patients, liberal use of blood transfusion, particularly after the initial unit, remains common in vascular surgery. We therefore sought to investigate the incremental risk of each additional unit of blood transfused intraoperatively for patients undergoing elective open repair of abdominal aortic aneurysm (AAA) with regards to postoperative mortality and complications.

METHODS

Patients in the Vascular Quality Initiative registry undergoing elective open infrarenal AAA repair from 2003 to 2020 were included. Exclusion criteria were age greater than 90, prior aortic surgery, concomitant iliac aneurysm, and concomitant additional major procedure. Multivariable logistic regression was used to calculate adjusted odds ratios for in-hospital mortality with incremental increases in packed red blood cells (pRBCs) given intraoperatively. Univariate analysis was performed for secondary outcomes including postoperative cardiac, respiratory, renal, and wound complications.

RESULTS

Of 4608 patients who underwent elective open AAA repair, 796 patients (16.9%) underwent perioperative transfusion. The overall in-hospital mortality rate was 2.5%. Adjusting for relevant factors, there was an increase in the odds of in-hospital mortality of 24% for each additional unit transfused. Incremental increases in the number of units transfused were associated with significantly higher risk of postoperative myocardial infarction, congestive heart failure, pulmonary complications, renal failure, and wound complications.

DISCUSSION

There appears to be an important increase in the odds of mortality for each additional unit transfused during infrarenal open AAA repair even when controlling for confounders.

Risk Factors for Surgical Site Infection after Lower Limb Revascularisation Surgery: a Systematic Review and Meta-Analysis of Prognostic Studies

OBJECTIVE

To systematically review and meta-analyse adjusted risk factors for surgical site infection (SSI) after lower limb revascularisation surgery.

DATA SOURCES

MEDLINE, Embase, Evidence Based Medicine Reviews, and the Cochrane Central Register of Controlled Trials (inception to 28 April 2022).

REVIEW METHODS

Systematic review and meta-analysis conducted according to PRISMA guidelines. After protocol registration, databases were searched. Studies reporting adjusted risk factors for SSI in adults who underwent lower limb revascularisation surgery for peripheral artery disease were included. Adjusted odds ratios (ORs) were pooled using random effects models. GRADE was used to assess certainty.

RESULTS

Among 6 377 citations identified, 50 studies (n = 271 125 patients) were included. The cumulative incidence of SSI was 12 (95% confidence interval [CI] 10 - 13) per 100 patients. Studies reported 139 potential SSI risk factors adjusted for a median of 12 (range 1 - 69) potential confounding factors. Risk factors that increased the pooled adjusted odds of SSI included: female sex (pooled OR 1.41, 95% CI 1.20 - 1.64; high certainty); dependent functional status (pooled OR 1.18, 95% CI 1.03 - 1.35; low certainty); being overweight (pooled OR 1.82, 95% CI 1.29 - 2.56; moderate certainty), obese (pooled OR 2.20, 95% CI 1.44 - 3.36; high certainty), or morbidly obese (pooled OR 1.65, 95% CI 1.08 - 2.52; moderate certainty); chronic obstructive pulmonary disease (pooled OR 1.42, 95% CI 1.17 - 1.71; high certainty); chronic limb threatening ischaemia (pooled OR 1.67, 95% CI 1.22 - 2.29; moderate certainty); chronic kidney disease (pooled OR 2.13, 95% CI 1.18 - 3.83; moderate certainty); intra-operative (pooled OR 1.23, 95% CI 1.02 - 1.49), peri-operative (pooled OR 1.92, 95% CI 1.27 - 2.90), or post-operative (pooled OR 2.21, 95% CI 1.44 - 3.39) blood transfusion (moderate certainty for all); urgent or emergency surgery (pooled OR 2.12, 95% CI 1.22 - 3.70; moderate certainty); vein bypass and or patch instead of endarterectomy alone (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty); an operation lasting ≥ 3 hours (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty) or ≥ 5 hours (pooled OR 1.60, 95% CI 1.18 - 2.17; moderate certainty); and early or unplanned re-operation (pooled OR 4.50, 95% CI 2.18 - 9.32; low certainty).

CONCLUSION

This systematic review identified evidence informed SSI risk factors following lower limb revascularisation surgery. These may be used to develop improved SSI risk prediction tools and to identify patients who may benefit from evidence informed SSI prevention strategies.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery

BACKGROUND

Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass.

METHODS

In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis.

RESULTS

A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03).

CONCLUSIONS

Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.

Drugs to reduce bleeding and transfusion in major open vascular or endovascular surgery: a systematic review and network meta-analysis

BACKGROUND

Vascular surgery may be followed by internal bleeding due to inadequate surgical haemostasis, abnormal clotting, or surgical complications. Bleeding ranges from minor, with no transfusion requirement, to massive, requiring multiple blood product transfusions. There are a number of drugs, given systemically or applied locally, which may reduce the need for blood transfusion.

OBJECTIVES

To assess the effectiveness and safety of anti-fibrinolytic and haemostatic drugs and agents in reducing bleeding and the need for blood transfusion in people undergoing major vascular surgery or vascular procedures with a risk of moderate or severe (> 500 mL) blood loss.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL, and Transfusion Evidence Library. We also searched the WHO ICTRP and ClinicalTrials.gov trial registries for ongoing and unpublished trials. Searches used a combination of MeSH and free text terms from database inception to 31 March 2022, without restriction on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults of drug treatments to reduce bleeding due to major vascular surgery or vascular procedures with a risk of moderate or severe blood loss, which used placebo, usual care or another drug regimen as control.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were units of red cells transfused and all-cause mortality. Our secondary outcomes included risk of receiving an allogeneic blood product, risk of reoperation or repeat procedure due to bleeding, risk of a thromboembolic event, risk of a serious adverse event and length of hospital stay. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 22 RCTs with 3393 participants analysed, of which one RCT with 69 participants was reported only in abstract form, with no usable data. Seven RCTs evaluated systemic drug treatments (three aprotinin, two desmopressin, two tranexamic acid) and 15 RCTs evaluated topical drug treatments (drug-containing bioabsorbable dressings or glues), including fibrin, thrombin, collagen, gelatin, synthetic sealants and one investigational new agent. Most trials were conducted in high-income countries and the majority of the trials only included participants undergoing elective surgery. We also identified two ongoing RCTs. We were unable to perform the planned network meta-analysis due to the sparse reporting of outcomes relevant to this review. Systemic drug treatments We identified seven trials of three systemic drugs: aprotinin, desmopressin and tranexamic acid, all with placebo controls. The trials of aprotinin and desmopressin were small with very low-certainty evidence for all of our outcomes. Tranexamic acid versus placebo was the systemic drug comparison with the largest number of participants (2 trials; 1460 participants), both at low risk of bias. The largest of these included a total of 9535 individuals undergoing a number of different higher risk surgeries and reported limited information on the vascular subgroup (1399 participants). Neither trial reported the number of units of red cells transfused per participant up to 30 days. Three outcomes were associated with very low-certainty evidence due to the very wide confidence intervals (CIs) resulting from small study sizes and low number of events. These were: all-cause mortality up to 30 days; number of participants requiring an allogeneic blood transfusion up to 30 days; and risk of requiring a repeat procedure or operation due to bleeding. Tranexamic acid may have no effect on the risk of thromboembolic events up to 30 days (risk ratio (RR) 1.10, 95% CI 0.88 to 1.36; 1 trial, 1360 participants; low-certainty evidence due to imprecision). There is one large ongoing trial (8320 participants) comparing tranexamic acid versus placebo in people undergoing non-cardiac surgery who are at high risk of requiring a red cell transfusion. This aims to complete recruitment in April 2023. This trial has primary outcomes of proportion of participants transfused with red blood cells and incidence of venous thromboembolism (DVT or PE). Topical drug treatments Most trials of topical drug treatments were at high risk of bias due to their open-label design (compared with usual care, or liquids were compared with sponges). All of the trials were small, most were very small, and few reported clinically relevant outcomes in the postoperative period. Fibrin sealant versus usual care was the topical drug comparison with the largest number of participants (5 trials, 784 participants). The five trials that compared fibrin sealant with usual care were all at high risk of bias, due to the open-label trial design with no measures put in place to minimise reporting bias. All of the trials were funded by pharmaceutical companies. None of the five trials reported the number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. The other three outcomes were associated with very low-certainty evidence with wide confidence intervals due to small sample sizes and the low number of events, these were: all-cause mortality up to 30 days; risk of requiring a repeat procedure due to bleeding; and risk of thromboembolic disease up to 30 days. We identified one large trial (500 participants) comparing fibrin sealant versus usual care in participants undergoing abdominal aortic aneurysm repair, which has not yet started recruitment. This trial lists death due to arterial disease and reintervention rates as primary outcomes.

AUTHORS' CONCLUSIONS

Because of a lack of data, we are uncertain whether any systemic or topical treatments used to reduce bleeding due to major vascular surgery have an effect on: all-cause mortality up to 30 days; risk of requiring a repeat procedure or operation due to bleeding; number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. There may be no effect of tranexamic acid on the risk of thromboembolic events up to 30 days, this is important as there has been concern that this risk may be increased. Trials with sample size targets of thousands of participants and clinically relevant outcomes are needed, and we look forward to seeing the results of the ongoing trials in the future.

Impact of Preoperative Anemia on Hospitalization, Death, and Overall Survival in Patients With Peripheral Artery Disease Undergoing Endovascular Therapy: A Retrospective Cohort Study in the United States and Canada

PURPOSE

Preoperative anemia is associated with adverse outcomes after cardiac and noncardiac surgeries, but outcomes after an endovascular peripheral vascular intervention (PVI) are not well established. We aimed to assess the association of preoperative anemia with 30 day death, hospital length of stay (LOS), and overall (long term) survival in patients undergoing an endovascular PVI for peripheral artery disease.

MATERIALS AND METHODS

In this retrospective, cohort study in the United States and Canada, we queried the national Vascular Quality Initiative database for all endovascular PVIs performed between 2010 and 2019, and outcomes were correlated with patients' hemoglobin (Hb) levels. Anemia was classified as mild (Hb=10-13 g/dL for men and 10-12 g/dL for women), moderate (Hb=8-9.9 g/dL), and severe (Hb<8 g/dL).

RESULTS

A total of 79 707 adult patients who met study criteria underwent endovascular PVI. The mean age was 68 years, and 59% of patients were male. Anemia was documented in 38 543 patients (48%) and was mild in 27 435 (71%), moderate in 9783 (25%), and severe in 1325 (4%). The median follow-up duration was 4 years (range, 1.25-5.78 years). On univariate analysis, 30 day mortality, total LOS, and overall survival were significantly associated with the level of preoperative anemia. These associations persisted in the multivariate models. Kaplan-Meier survival analysis demonstrated an association of death with degree of anemia (p<0.001).

CONCLUSION

The presence and degree of preoperative anemia were independently associated with increased 30 day mortality and LOS and decreased overall survival for patients with peripheral artery disease who had undergone endovascular PVI.

CLINICAL IMPACT

The findings from this study have many implications for how to approach vascular surgery in patients with variable hemoglobin levels. Our findings will strengthen our ability to conduct accurate preoperative risk stratification for patients undergoing peripheral vascular interventions. This may also mitigate healthcare expenditures if findings are applied in a way that can lower patient length of postoperative stay while also maintaining quality of care and patient safety. Our results will also serve as guidance for clinical trials, and future prospective trials should evaluate the effect of preoperative optimization of hemoglobin as a potentially modifiable risk factor for outcomes.

Development and internal validation of a nomogram to predict massive blood transfusions in neurosurgical operations

Objectives

A massive blood transfusion (MBT) is an unexpected event that may impact mortality. Neurosurgical operations are a major operation involving the vital structures and risk to bleeding. The aims of the present research were (1) to develop a nomogram to predict MBT and (2) to estimate the association between MBT and mortality in neurosurgical operations.

Material and Method

We conducted a retrospective cohort study including 3660 patients who had undergone neurosurgical operations. Univariate and multivariate logistic regression analyses were used to test the association between clinical factors, pre-operative hematological laboratories, and MBT. A nomogram was developed based on the independent predictors.

Results

The predictive model comprised five predictors as follows: Age group, traumatic brain injury, craniectomy operation, pre-operative hematocrit, and pre-operative international normalized ratio and the good calibration were observed in the predictive model. The concordance statistic index was 0.703. Therefore, the optimism-corrected c-index values of cross-validation and bootstrapping were 0.703 and 0.703, respectively.

Conclusion

MBT is an unexpectedly fatal event that should be considered for appropriate preparation blood components. Further, this nomogram can be implemented for allocation in limited-resource situations in the future.

Association of Intraoperative and Perioperative Transfusions with Postoperative Cardiovascular Events and Mortality after Infrainguinal Revascularization

BACKGROUND

Patients undergoing open or endovascular infrainguinal revascularization are at elevated risk for postoperative cardiovascular complications due to high rates of comorbidities and the physiologic stress of surgery. Transfusions are known to be associated with adverse events, but knowledge of specific risks associated with transfusion timing, product type, and long-term outcomes while accounting for preoperative cardiovascular risk factors is not well understood in this population.

AIM

This study aimed to characterize the association of intraoperative and perioperative transfusion, anemia, and cardiovascular risk factors with cardiovascular events and mortality in patients undergoing infrainguinal revascularization.

METHODS

A single-center retrospective study was performed on 564 infrainguinal revascularization procedures, including both open (n=250) and endovascular (n=314) approaches (2016-2020). Comprehensive clinical data were collected including patient demographics, cardiovascular risk factors, preoperative hemoglobin, and detailed transfusion data. Multivariable logistic regression tested the association of transfusions with composite 30-day outcomes of cardiac complications (postoperative myocardial infarction [postop-MI], congestive heart failure [CHF], or dysrhythmia) and with major adverse cardiovascular events (MACE- postop-MI or death). Kaplan-Meier analysis and cox-proportional hazard modeling examined the association of transfusions, anemia, and cardiovascular risk factors with mortality up to 1 year.

RESULTS

Intraoperative transfusion was performed in 15% of cases and 13% underwent transfusion in the early postoperative period. Intraoperative transfusion was associated with higher Revised Cardiac Risk Index (RCRI), lower preoperative hemoglobin, increased blood loss and open procedures (all p<0.05). Within each RCRI score, intraoperative transfusion was associated with 2-4 fold increased MACE at 30 days. Intraoperative pRBC transfusion and early postoperative pRBC transfusion was associated with more than 2-fold adjusted odds of any cardiovascular complication and intraoperative transfusion was also associated with MACE (all p<0.05). Intraoperative transfusion was associated with mortality at one year on unadjusted analysis, but after adjustment for RCRI, age, and preoperative hemoglobin, only RCRI scores of 2 and 3+ and preoperatively hemoglobin remained significant risk factors for mortality.

CONCLUSIONS

Intraoperative and early perioperative transfusions are strongly associated with worse cardiovascular outcomes after infrainguinal revascularization. These findings may have prognostic value for further risk stratifying patients perioperatively at high risk for complications. However, prospective studies are needed to elucidate whether optimizing transfusion strategies mitigates these risks.

High Rates of Recurrent Revascularization in Acute Limb Ischemia - a National Surgical Quality Improvement Program Study

OBJECTIVES

We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to review outcomes of acute limb ischemia (ALI) patients following open surgical intervention for ALI.

METHODS

A previously validated tool was used to identify ALI patients in NSQIP undergoing open surgical revascularization from 2012-2017. Multivariable analysis was performed for the primary outcome of reoperation and secondary outcome of readmission and infection.

RESULTS

2,878 ALI patients underwent open revascularization; 35.7% were transfers from another acute care hospital. 13.8% required reoperation and 7.9% required readmission within 30 days. 32% of reoperations were recurrent revascularization, representing 4.4% of all ALI patients. 58.7% of patients were female and either overweight or obese. Younger age (OR 0.991 [0.984-0.999], p=0.02), underweight patients (OR 1.159 [0.667-2.01], p=0.05), pre-operative steroid use (OR 1.61 [1.07-2.41], p=0.02), and perioperative transfusion (OR 2.02 [1.04-3.95], p=0.04) predicted reoperations.

CONCLUSIONS

This registry series demonstrates all-cause ALI patients are a different population than PAD with different risk factors. Despite being a time-critical condition, ALI has higher interhospital transfer rates than ACS or ruptured aneurysm. Following open revascularization, ALI outcomes are worse than ACS but better than ruptured AAA. These outcomes do not appear related to patient factors in contrast to revascularization for chronic PAD.

Impact of Perioperative Blood Transfusion in Anemic Patients Undergoing Infra Inguinal Bypass

OBJECTIVE

Patients who present with lower extremity ischemia are frequently anemic and the optimal transfusion threshold for this cohort remains controversial. We sought to evaluate the impact of blood transfusion on postoperative major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients.

METHODS

All consecutive patients who underwent infra-inguinal bypass at our institution from 2011 to 2020 were included. Perioperative red blood cell transfusion was the primary exposure, and the primary outcome was MACE. Univariate and multivariable analyses were performed to assess the impact of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hgb) nadir: <7, 7-8, and >8 g/dL.

RESULTS

Of the 287 patients reviewed for analysis, 146 (50.9%) had a perioperative transfusion (mean: 1.6 ± 3 units). Patients who received a transfusion had a mean nadir Hgb of 8.3 ± 1.0 g/dL, compared to 10.1 ± 1.7 g/dL without a transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = 0.009), lower Hgb nadir (P = 0.02), and higher blood loss (P = 0.003). On multivariate analysis, transfusion was independently associated with MACE for patients with a Hgb nadir >8 g/dL (OR: 3.09; P = 0.006), but not for patients with Hgb nadir 7-8 g/dL (OR: 0.818; P = 0.77). Additionally, patients with MACE had significantly longer length of hospital stay than for patients without (13 vs. 7.7 days, P = 0.001).

CONCLUSIONS

For patients undergoing infra-inguinal bypass, receiving a red blood cell transfusion with a Hgb nadir >8 g/dL was associated with a 3-fold increase in MACE, with nearly twice the length of stay. For patients with a Hgb 7-8 g/dL, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusion for patients with Hgb nadir >7 g/dL and harm for Hgb >8 g/dL, however causation cannot be proven due to the retrospective nature of the study and randomized studies are needed to confirm or refute these findings.

Anaemia: A risk factor for death and adverse outcomes following surgery for acute lower limb ischaemia

INTRODUCTION

Acute limb ischaemia (ALI) forms a significant part of the vascular surgery workload and carries with it high rates of morbidity and mortality. Anaemia is also common amongst vascular surgical patients and has been linked with poor outcomes in some subgroups. We aimed to assess the frequency of anaemia in patients with ALI and its impact on survival and complications following revascularisation to help direct future efforts to optimise outcomes in this patient group.

METHODS

A retrospective analysis of prospectively collected departmental data on patients undergoing surgical intervention for ALI between 2014 and 2018 was performed. Anaemia was defined as a pre-operative haemoglobin (Hb) of <120 g/L for women and <130 g/L for men. The primary outcome was overall survival, assessed with the Kaplan-Meier estimator, with application of Cox proportional hazard modelling to adjust for confounding covariates.

RESULTS

There were 158 patients who underwent treatment for ALI: 89 (56.3%) of these were non-anaemic with a mean Hb of 146 (SD = 18.4), and 69 (43.7%) were anaemic with a mean Hb of 106 (SD = 13.4). Anaemic patients had a significantly higher risk of death than their non-anaemic counterparts on univariate analysis (HR = 2.11, 95% CIs, 1.28-3.5, p = 0.0036). There was ongoing divergence in survival up to around 6 months between anaemic and non-anaemic groups. Under the Cox model, anaemia was similarly significant as a predictor of death (HR = 2.15, 95% CIs, 1.17-3.95, p = 0.013), accounting for recorded comorbidities, medication use and blood transfusion.

CONCLUSIONS

Anaemia is a significant and independent risk factor for death following revascularisation for ALI and can be potentially be modified. Vascular surgical centres should ensure they have robust pathways in place to identify and consider treating anaemia. There is scope for further work to assess how to best optimise a patient's levels of circulating haemoglobin.

Real-world results of the implementation of preoperative anaemia clinic with intravenous iron therapy for treating iron-deficiency anaemia: a propensity-matched case-control study

Background

Preoperative anaemia is associated with blood transfusion and longer hospital length of stay. Preoperative iron deficiency anaemia (IDA) can be treated with oral or intravenous (IV) iron. IV iron can raise haemoglobin faster compared with oral iron. However, its ability to reduce blood transfusion and length of stay in clinical trials is inconclusive. This study aims to compare blood transfusion and hospital length of stay between anemic patients who received preoperative IV iron versus standard care, after implementation of a protocol in 2017 to screen patients for preoperative IDA, and its treatment with IV iron.

Methods

Retrospective before-after cohort study comparing 89 patients who received IV iron preoperatively in 2017, with historic patients who received oral iron therapy (selected by propensity score matching (PSM) from historic cohort of 7,542 patients who underwent surgery in 2016). Propensity score was calculated using ASA status, age, gender, surgical discipline, surgical risk and preoperative haemoglobin concentration. Both 1:1 and 1:2 matching were performed as sensitivity analysis.

Results

After PSM, there was no statistically significant difference in distribution of preoperative clinical variables. There was no significant difference in proportion of cases requiring transfusion nor a difference in average units transfused per patient. IV iron cohort stayed in hospital on average 8.0 days compared to non-IV iron cohort 14.1–15.1 days (P=0.006, P=0.013 respectively). Average time from IV iron therapy to surgery was 10.5 days.

Conclusions

Preoperative IV iron therapy for patients with IDA undergoing elective surgery may not reduce perioperative blood transfusion, but this could be due to the short time between therapy and surgery. Implementation of IV iron therapy may reduce hospital length of stay compared to standard care for anemic patients, although this may be enhanced by concomitant improvement in perioperative care.

Long-term Impact of Perioperative Red Blood Cell Transfusion on Patients Undergoing Cardiac Surgery

BACKGROUND

There is a known association between need for transfusion and short-term outcomes in patients undergoing cardiac surgery. However long-term data are lacking in the contemporary literature.

METHODS

All patients who underwent open cardiac surgery from 2010 to 2018 were included, except those undergoing transplant, with a ventricular-assist device, and requiring circulatory arrest. Primary outcome included short- and long-term mortality. Secondary outcomes included postoperative complications and hospital readmissions.

RESULTS

The total patient population included 14,281 patients with a median follow-up of 4.03 years (range, 2.25-6.1). Outcomes were stratified into patients with (n = 6239) or without (n = 8042) packed red blood cell (PRBC) use. Patients with PRBC transfusions had significantly (P < .001) worse postoperative outcomes compared with those without PRBC use, including higher operative mortality (6.89% vs 0.98%), return to the operating room (17.8% vs 1.61%), pneumonia (7.84% vs 0.98%), stroke (3.22% vs 1.51%), sepsis (2.66% vs 0.20%), renal failure (8.42% vs 1.12%), and dialysis (5.74% vs 0.42%). On multivariate analysis PRBC transfusion was an independent predictor of mortality (hazard ratio [[HR], 2.39; 95% confidence interval [CI], 2.08-2.64; P < .001) and hospital readmission (HR, 1.15; 95% CI, 1.09-1.21; P < .001). Total units of PRBCs were directly associated with mortality (HR, 1.09; 95% CI, 1.08-1.09; P < .001) and hospital readmissions (HR, 1.02; 95% CI, 1.01-1.03; P < .005).

CONCLUSIONS

Patients with perioperative PRBC transfusions have increased operative and long-term mortality and hospital readmissions. Total units of PRBCs transfused were directly associated with mortality and readmissions.

Postoperative anemia is a risk factor for acute kidney injury after open aorta and vena cava surgeries

Open aorta and vena cava surgeries are usually associated with substantial blood loss which may result in postoperative acute kidney injury (AKI). The present study is designed to investigate the prevalence, outcome and risk factors of postoperative AKI associated with open aorta and vena cava surgeries, with a focus on the role of anemia in these conditions. A retrospective review of medical records of Peking Union Medical College Hospital was conducted. Patients who underwent open aorta and vena cava surgeries during January 1, 2010 and June 30, 2014 were included in this study. The primary analysis was between patients underwent open aorta and vena cava surgeryies, with or without postoperative AKI. Multivariable logistic regression models were used to determine risk factors of postoperative AKI. The study included 79 patients (63.3% male) with a mean age of 52.5±17.3 years (range, 17–81 years). Postoperative AKI occurred in 23/79 (29.1%) of the patients. Anemia was present in 11/79 (16%) at baseline, and increased to 45/79 (52%) postoperatively. After adjustment for various risk factors, postoperative anemia (OR, 5.202; 95% CI 1.403–19.285) was independently associated with postoperative AKI. AKI is a common complication in patients who undergo open aorta and vena cava surgeries, and postoperative anemia was the most relevant predictive factor of AKI. Strategies to minimize bleeding and anemia for all patients may be advisable. Further studies are needed to assess the impact of AKI on long term outcome and to examine preventive strategies to address potentially modifiable risk factors.

The association between preoperative length of stay and surgical site infection after lower extremity bypass for chronic limb-threatening ischemia

OBJECTIVE

Surgical site infection (SSI) is an important complication of lower extremity bypass (LEB) and the rate of SSI after LEB varies widely in the existing literature, ranging from 4% to 31%. Prolonged length of stay (LOS) has been implicated in the occurrence of SSI across multiple surgical disciplines. The impact of preoperative LOS in patients with chronic limb-threatening ischemia (CLTI) undergoing LEB is unknown. We examined the association of preoperative LOS on SSI after LEB.

METHODS

A retrospective analysis of the Society for Vascular Surgery Vascular Quality Initiative Infrainguinal Bypass Registry identified patients undergoing elective LEB for chronic limb-threatening ischemia from 2003 to 2019. Patients undergoing LEB for acute limb ischemia, urgent/emergent procedures, aneurysm, or who had concomitant suprainguinal bypass were excluded. The primary outcome measure was postoperative SSI. Multivariable forward stepwise logistic regression was then performed including all variables with a P value of less than .10 in both matched and unmatched cohorts to evaluate for demographic and perioperative predictors of SSI. Propensity score matching was used to create matched cohorts of patients for each LOS group.

RESULTS

A total of 17,883 LEB procedures were selected for inclusion: 0 days (12,362 LEB), 1 to 2 days (1737 LEB), and 3 to 14 days (3784 LEB). Patients with the greatest preoperative LOS were more likely to have vein mapping (0 days preoperative LOS, 66.3%; 1-2 days, 65.2%; 3-14 days, 73.2%; P < .01) or computed tomography angiography/magnetic resonance angiography (0 days, 32.1%; 1-2 days, 34.4%; 3-14 days, 38.4%; P < .01). Patients with 3 or more days of preoperative LOS had longer procedure lengths (0 days, 244 minutes; 1-2 days, 243 minutes; 3-14 days, 255 minutes; P < .01) and were more likely to have completion angiogram (0 days, 27.1%; 1-2 days, 29.5%; 3-14 days, 31.6%; P = .02). Multivariable logistic regression demonstrated that preoperative LOS of 3 to 14 days was associated with increased rate of SSI (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.20-3.07; P = .01). Transfusion of 3 or more units (OR, 2.87; 95% CI, 1.89-4.36; P < .01) and prolonged procedure length (>220 minutes; OR, 1.86; 95% CI, 1.26-2.73; P < .01) were also significantly associated with postoperative SSIs.

CONCLUSIONS

Many factors including preoperative comorbidities and operative complexity covary with preoperative LOS as risk factors for SSI. However, when patients are matched based on comorbidities and factors that would predict overall clinical complexity, preoperative LOS remains important in predicting SSI.

Predictors and Outcomes of Cardiac Events following Thoracic Endovascular Aortic Repair in Descending Thoracic Aortic Aneurysm and Dissection

BACKGROUND

 Cardiac events following thoracic endovascular aortic repair (TEVAR) have been associated with significant morbidity and mortality. However, predictors of post-TEVAR cardiac events in descending thoracic aortic aneurysm or dissection are poorly understood.

METHODS

 A retrospective analysis of completed TEVAR procedures performed from 2010 to 2016 was conducted using the ACS-NSQIP (American College of Surgeons National Surgical Quality Improvement Program) participant user file database. Adult patients (≥18 years) who underwent TEVAR for descending thoracic aortic aneurysm or dissection were identified and 30-day outcomes were examined. An initial univariate analysis was performed to determine associations between all patient variables and cardiac events, defined as myocardial infarction or cardiac arrest that occurred ≤30 days of surgery. Multivariate logistic regression was subsequently performed to identify independent risk factors for cardiac events following TEVAR.

RESULTS

 The study identified 150 out of 2,905 (5.2%) patients who underwent TEVAR for descending thoracic aortic aneurysm or dissection who developed cardiac events. No significant difference in incidence of cardiac events was noted among patients presenting with aortic aneurysm or dissection (p = 0.339). The overall 30-day mortality rate for all patients was 9.1%. Independent preoperative predictors of post-TEVAR cardiac events included emergency procedure (odds ratio [OR] 2.80, 95% confidence interval [CI] 1.9-4.1, p < 0.01); American Society of Anesthesiologists score >3 (OR 1.71, 95% CI 1.1-2.6, p = 0.01), ventilator dependence (OR 2.33, 95% CI 1.3-4.2, p < 0.01), renal failure (OR 2.53, 95% CI 1.50-4.3, p < 0.01), blood transfusion (OR 1.84, 95% CI 1.1-3.2, p = 0.03), and preoperative leukocytosis (OR 2.45, 1.6-3.8, p < 0.01). After TEVAR, unplanned reintubation (OR 5.52, 95% CI 3.5-8.8, p < 0.01), prolonged mechanical ventilation (OR 1.94, 95% CI 1.2-3.2, p = 0.011), and postoperative blood transfusion (OR 4.02, 95% CI 2.70-6.0, p < 0.01) were independent predictors of cardiac events. Cardiac events greatly increased mortality (60.7 vs. 5.5%), total length of hospital stay (13.2 ± 14.7 days vs. 8.3 ± 9.3 days), and readmission rates (19.3 vs. 8.2%, p < 0.01).

CONCLUSIONS

 Cardiac events following TEVAR are associated with significant mortality. Patients with these risk factors should be appropriately monitored to improve outcomes.

Transfusion Timing and Postoperative Myocardial Infarction and Death in Patients Undergoing Common Vascular Procedures

BACKGROUND

Perioperative allogenic blood transfusions, specifically packed red bloods cells (pRBC), after vascular surgery procedures are modifiable risk factors that are associated with increased cardiovascular events and 30-day mortality. The aim of this study is to evaluate the effect of transfusion timing (intraoperative vs. postoperative) on the rate of postoperative myocardial infarction (POMI) and death.

METHODS

Six surgical and endovascular modules within the Vascular Quality Initiative (VQI) from 2013 to 2017 were reviewed at a single institution. Transfusion data on elective and urgent cases were abstracted and all patients who underwent inpatient procedures had routine postoperative troponin/ECG testing. The primary endpoint was POMI utilizing the American Heart Association's third universal definition for myocardial infarction. These criteria include the detection of a rise/and or fall of cTnT with at least one value above the 99th percentile and with at least one of the following 1) symptoms of acute myocardial ischemia, 2) new ischemic ECG changes, 3) development of pathological Q waves, 4) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality in a pattern consistent with ischemic etiology. The secondary endpoint was 30-day all-cause mortality. Multivariable logistic regression analysis was utilized to evaluate the risk of transfusions on POMI and death.

RESULTS

We identified 1,154 cases for analysis (299 abdominal aortic aneurysm [EVAR], 117 infrainguinal bypasses, 127 open abdominal aortic aneurysm [AAA], 41 suprainguinal bypasses, 168 thoracic endovascular aortic repair [TEVAR], and 402 peripheral vascular interventions). Overall, the POMI rate was 2% and mortality 1%. Rates of POMI differed by procedure type (P = 0.04), where infrainguinal bypass had the highest rate of POMI at 4%. Death rates did not vary by type of procedure (P = 0.89). Mean number of intraoperative pRBC and postoperative pRBC transfusion was higher for patients with POMI (intraop: 1.3 vs. 0.3, postop: 1.8 vs. 0.4, both P < 0.01) and death (intraop: 1.4 vs. 0.3, postop: 2.5 vs. 0.4, both P < 0.01). In addition, older age and coronary artery disease (CAD) were associated with POMI on univariate analysis. On multivariable analysis for POMI, CAD (odds ratio [OR] = 5.15, 95% confidence interval [CI] [2.00-13.24], P < 0.001), receiving both an intraoperative and postoperative transfusion (OR = 6.20, 95% CI [1.78-21.55], P < 0.01) as well as a postoperative transfusion only (OR = 5.70, 95% CI [1.81-17.94], P < 0.01) compared to no transfusion were associated with higher odds of POMI; however intraoperative transfusion only was not (OR = 3.42, 95% CI [0.88-13.31], P = 0.08). On multivariable analysis, increasing age of the patient was associated with higher odds of death (OR = 1.08, 95% CI [1.01-1.15], P = 0.02) and statin use was highly protective (OR = 0.27, 95% CI [0.10-0.74], P = 0.01), but any intraoperative or postoperative transfusion compared to no transfusion was not associated with death after adjustment.

CONCLUSIONS

In our series with routine postoperative troponin screening in the inpatient setting, the use of an isolated postoperative transfusion as well as cases requiring both an intraoperative and postoperative transfusion was associated with POMI. However, isolated intraoperative transfusion was not associated with POMI, and we did not identify an association of transfusion with 30-day mortality. These data suggest that the perioperative setting of transfusions is important in its impact on postoperative outcomes and needs to be accounted for when evaluating transfusion outcomes and indications.

Clinical Features and Outcomes of Peripheral Vascular Disease Patients Receiving Red Blood Cell Transfusions

Background Peripheral vascular disease (PVD) patients are commonly transfused with red blood cells (RBC) due to their inability to compensate for anemia and blood loss. Anemias, as well as allogeneic transfusions, have been demonstrated as independent risk factors for increased mortality and morbidity following cardiovascular procedures. The relationships between anemia, transfusion, and adverse outcomes in PVD patients remain unascertained and understudied. Methods A retrospective cohort study was conducted to determine mortality at 30-day, one-year, and three-year markers among 330 randomly selected PVD patients. The clinical features of patients receiving transfusions were examined, and the mortality rates were compared between patients who received an RBC transfusion and those who did not. Cox regression analysis was employed to identify independent variables predicting mortality. Results Transfusions were found to have increased mortality rates over non-transfused patients at 30 days (6.1% vs. 1.8%, p = 0.05), one year (21.8% vs 12.1%, p = 0.02), and three years (41.2% vs. 23.0%, p = 0.001). Using a multivariate regression model, it was determined that the transfusion itself was not a significant cause of this decrease in survival, while the propensity to transfuse was a predictor for both short (30 days, 36.73 [1.85-728.06], p = 0.04) and long-term mortality (one year (8.83 [2.62-29.77], p < 0.001; three years (7.07 [1.46-8.07], p <0.01). Anti-coagulation therapy using intravenous (IV) heparin and the chronic comorbidities of coronary artery disease and diabetes mellitus were also robust independent predictors of decreased survival. Conclusion This study was able to find an association between RBC transfusion and reduction in short-term (three months) and long-term (three years) survival. Those requiring IV heparin during the hospital stay were at an increased risk of requiring blood transfusion, and patients receiving IV heparin were also found to have a significant increase in mortality rates.

Preoperative Albuminuria and Intraoperative Chloride Load: Predictors of Acute Kidney Injury Following Major Abdominal Surgery

Background: Postoperative Acute Kidney Injury (AKI) is a common and serious complication associated with significant morbidity and mortality. While several pre- and intra-operative risk factors for AKI have been recognized in cardiac surgery patients, relatively few data are available regarding the incidence and risk factors for perioperative AKI in other surgical operations. The aim of the present study was to determine the risk factors for perioperative AKI in patients undergoing major abdominal surgery. Methods: This was a prospective, observational study of patients undergoing major abdominal surgery in a tertiary care center. Postoperative AKI was diagnosed according to the Acute Kidney Injury Network criteria within 48 h after surgery. Patients with chronic kidney disease stage IV or V were excluded. Logistic regression analysis was used to evaluate the association between perioperative factors and the risk of developing postoperative AKI. Results: Eleven out of 61 patients developed postoperative AKI. Four intra-operative variables were identified as predictors of AKI: intra-operative blood loss (p = 0.002), transfusion of fresh frozen plasma (p = 0.004) and red blood cells (p = 0.038), as well as high chloride load (p = 0.033, cut-off value > 500 mEq). Multivariate analysis demonstrated an independent association between AKI development and preoperative albuminuria, defined as a urinary Albumin to Creatinine ratio ≥ 30 mg·g⁻¹ (OR = 6.88, 95% CI: 1.43–33.04, p = 0.016) as well as perioperative chloride load > 500 mEq (OR = 6.87, 95% CI: 1.46–32.4, p = 0.015). Conclusion: Preoperative albuminuria, as well as a high intraoperative chloride load, were identified as predictors of postoperative AKI in patients undergoing major abdominal surgery.

Epidemiology, outcomes, and management of acute kidney injury in the vascular surgery patient

OBJECTIVE

Conventional clinical wisdom has often been nihilistic regarding the prevention and management of acute kidney injury (AKI), despite its being a frequent and morbid complication associated with both increased mortality and cost. Recent developments have shown that AKI is not inevitable and that changes in management of patients can reduce both the incidence and morbidity of perioperative AKI. The purpose of this narrative review was to review the epidemiology and outcomes of AKI in patients undergoing vascular surgery using current consensus definitions, to discuss some of the novel emerging risk stratification and prevention techniques relevant to the vascular surgery patient, and to describe a standardized perioperative pathway for the prevention of AKI after vascular surgery.

METHODS

We performed a critical review of the literature on AKI in the vascular surgery patient using the PubMed and MEDLINE databases and Google Scholar through September 2017 using web-based search engines. We also searched the guidelines and publications available online from the organizations Kidney Disease: Improving Global Outcomes and the Acute Dialysis Quality Initiative. The search terms used included acute kidney injury, AKI, epidemiology, outcomes, prevention, therapy, and treatment.

RESULTS

The reported epidemiology and outcomes associated with AKI have been evolving since the publication of consensus criteria that allow accurate identification of mild and moderate AKI. The incidence of AKI after major vascular surgery using current criteria is as high as 49%, although there are significant differences, depending on the type of procedure performed. Many tools have become available to assess and to stratify the risk for AKI and to use that information to prevent AKI in the surgical patient. We describe a standardized clinical assessment and management pathway for vascular surgery patients, incorporating current risk assessment and preventive strategies to prevent AKI and to decrease its complications. Patients without any risk factors can be managed in a perioperative fast-track pathway. Those patients with positive risk factors are tested for kidney stress using the urinary biomarker TIMP-2•IGFBP7, and care is then stratified according to the result. Management follows current Kidney Disease: Improving Global Outcomes guidelines.

CONCLUSIONS

AKI is a common postoperative complication among vascular surgery patients and has a significant impact on morbidity, mortality, and cost. Preoperative risk assessment and optimal perioperative management guided by that risk assessment can minimize the consequences associated with postoperative AKI. Adherence to a standardized perioperative pathway designed to reduce risk of AKI after major vascular surgery offers a promising clinical approach to mitigate the incidence and severity of this challenging clinical problem.

Impact of perioperative blood transfusion on clinical outcomes in patients with colorectal liver metastasis after hepatectomy: a meta-analysis

BACKGROUND

Perioperative blood transfusion may be associated with negative clinical outcomes in oncological surgery. A meta-analysis of published studies was conducted to evaluate the impact of blood transfusion on short- and long-term outcomes following liver resection of colorectal liver metastasis (CLM).

MATERIALS AND METHODS

A systematic search was performed to identify relevant articles. Data were pooled for meta-analysis using Review Manager version 5.3.

RESULTS

Twenty-five observational studies containing 10621 patients were subjected to the analysis. Compared with non-transfused patients, transfused patients experienced higher overall morbidity (odds ratio [OR], 1.98; 95% confidence intervals [CI] =1.49-2.33), more major complications (OR, 2.12; 95% CI =1.26-3.58), higher mortality (OR, 4.13; 95% CI =1.96-8.72), and longer length of hospital stay (weighted mean difference, 4.43; 95% CI =1.15-7.69). Transfusion was associated with reduced overall survival (risk ratio [RR], 1.24, 95% CI =1.11-1.38) and disease-free survival (RR, 1.38, 95% CI=1.23-1.56).

CONCLUSION

Perioperative blood transfusion has a detrimental impact on the clinical outcomes of patients undergoing CLM resection.

Packed Red Blood Cell Transfusion in Older Adults: A Systematic Review

Most packed red blood cell (PRBC) transfusion research focuses on younger patient populations (younger than 65) given the complexity of care and presence of comorbidities in older adults. The purpose of the current study was to critically examine the current evidence related to PRBC transfusion among older adults (age ≥65). PubMed, CINAHL, and Embase were searched for randomized controlled trials that evaluated blood transfusion in any manner (e.g., prevention, associated outcomes). Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the search resulted in 10 studies focused on cardiac, orthopedic, and gastrointestinal surgery patients. SQUIRE (Standards for QUality Improvement Reporting Excellence) guidelines were used to evaluate studies for bias; the average bias score was 13.0 (SD = 3.4), indicating a low level of bias. Greatest sources of bias were methods to assess completeness/accuracy of data, details about missing data, and costs associated with the study. Interventions to prevent PRBC transfusion in older adults vary widely, and outcomes associated with PRBC transfusion in older adults require further evaluation. [Journal of Gerontological Nursing, 44(3), 39-46.].

A model-based cost-effectiveness analysis of Patient Blood Management

BACKGROUND

Patient blood management (PBM) is a multidisciplinary concept focused on the management of anaemia, minimisation of iatrogenic blood loss and rational use of allogeneic blood products. The aims of this study were: (i) to analyse post-operative outcome in patients with liberal vs restrictive exposure to allogeneic blood products and (ii) to evaluate the cost-effectiveness of PBM in patients undergoing surgery.

MATERIALS AND METHODS

A systematic literature review and meta-analysis were performed to compare post-operative complications in predominantly non-transfused patients (restrictive transfusion group) and patients who received one to three units of red blood cells (liberal transfusion group). Outcome measures included sepsis with/without pneumonia, acute renal failure, acute myocardial infarction and acute stroke. In a second step, a health economic model was developed to calculate cost-effectiveness of PBM (PBM-arm vs control-arm) for simulated cohorts of 10,000 cardiac and non-cardiac surgical patients based on the results of the meta-analysis and costs.

RESULTS

Out of 478 search results, 22 studies were analysed in the meta-analysis. The pooled relative risk of any complication in the restrictive transfusion group was 0.43 for non-cardiac and 0.34 for cardiac surgical patients. In the simulation model, PBM was related to reduced complications (1,768 vs 1,245) and complication-related deaths (411 vs 304) compared to standard care. PBM-related costs of therapy exceeded costs of the control arm by € 150 per patient. However, total costs, including hospitalisation, were higher in the control-arm for both non-cardiac (€ 2,885.11) and cardiac surgery patients (€ 1,760.69). The incremental cost-effectiveness ratio including hospitalisation showed savings of € 30,458 (non-cardiac and cardiac surgery patients) for preventing one complication and € 128,023 (non-cardiac and cardiac surgery patients) for prevention of one complication-related death in the PBM-arm.

DISCUSSION

Our results indicate that PBM may be associated with fewer adverse clinical outcomes compared to control management and may, thereby, be cost-effective.

Management and Outcome of Prosthetic Vascular Graft Infections: A Single Center Experience

Background:

Prosthetic vascular graft infection (PVGI) remains a severe and challenging complication in vascular surgery with high morbidity and mortality rates. Incidence has been reported between 1% and 6%. The aim of this study was to report our experience in terms of general and surgical management as well as outcome, over 15 years.

Methods:

A retrospective consecutive study was conducted of all patients treated in our department for PVGI between January 2000 and December 2015. We analyzed all data relative to primary operation, duration interval between initial surgery and infections signs, infection site, type of microorganism involved, and surgical treatment modality, as well as evaluation of short- and long-term results.

Results:

Sixty-two patients were admitted for PVGI. Primary revascularization procedures consisted of a peripheral bypass in 42 (68%) patients and an aortic bypass in the remaining 20 (32%) patients. Median interval between primary procedure and reintervention was 3 months (interquartile range 17 [IQR 17]) in the peripheral group and 48 months (IQR 70.5) in the aortic group. Complete excision of the prosthetic graft was carried out in 85% of the cases. Thirty-day mortality was 0% and 9.5% in the aortic and peripheral group, respectively. The overall survival rate was 62.3% at 2-years, 46.4% in the aortic group, and 69.7% in the peripheral group.

Conclusions:

Prosthetic vascular graft infection needs a multidisciplinary management with appropriate antibiotherapy, radical removal of the infected graft, and in situ reconstruction. This strategy gives satisfactory results in terms of mortality, morbidity, patency rates, and infection control.

Risk Factors Associated with Perioperative Myocardial Infarction in Major Open Vascular Surgery

BACKGROUND

Among patients undergoing noncardiac surgery, major vascular surgery is associated with a high risk of perioperative myocardial infarction (MI). Currently, there are no perioperative MI risk calculators accounting for intraoperative and postoperative risk factors in vascular surgery patients. We aimed to investigate specific risk factors for perioperative MI after major open vascular surgery to determine which patients are at highest risk of MI and the association of perioperative MI with perioperative transfusion.

METHODS

This statewide, retrospective cohort study analyzed risk factors for perioperative MI in major open vascular surgery between July 2012 and December 2015 using the Michigan Surgical Quality Collaborative, a multicenter quality collaborative. Patients were identified using current procedure terminology codes including open abdominal aortic aneurysm repairs (oAAA), aortobifemoral bypasses (AFB), and lower extremity bypasses (LEB). Rates of myocardial infarction were described for each procedure. A priori, preoperative, intraoperative, and postoperative variables were evaluated using univariate and multivariable statistics after adjusting for intraoperative factors including anesthesia type, intraoperative blood loss, intraoperative transfusion, and intraoperative vasopressor medications.

RESULTS

A total of 3,689 patients underwent major open vascular surgery, including 375 oAAA, 392 AFB, and 2,922 LEB procedures. The overall incidence of MI was 2.4%, varying from 1.8% for aortobifemoral bypass, 2.4% for lower extremity bypass, and 3.7% for open abdominal aortic aneurysm repair. Although preoperative risk factors for myocardial infarction included age, American Society of Anesthesiologists score, diabetes, coronary artery disease, congestive heart failure, use of beta blocker, lower preoperative hematocrit, and surgical priority (urgent/emergent cases), after adjusting for intraoperative risk factors, all preoperative risk factors were not significant with the exception of surgical priority. After adjusting for intraoperative factors, only surgical priority (odds ratio [OR] = 1.70, 95% confidence interval [CI] [1.01-2.85], P < 0.001) and postoperative transfusion (OR = 2.65, 95% CI [1.59-4.44], P < 0.001) was associated with myocardial infarction, and higher nadir hematocrit was inversely associated with myocardial infarction (OR = 0.89, 95% CI [0.85-0.94], P < 0.001).

CONCLUSIONS

Among vascular surgery patients undergoing major open vascular surgery, surgical priority was the only preoperative risk factors independently associated with MI, and only postoperative variables such as nadir hematocrit and postoperative transfusion were associated with MI. This suggests minimizing intraoperative blood loss and prioritizing early intraoperative transfusion may be the potential targets for process improvement.

Preoperative anemia associated with adverse outcomes after infrainguinal bypass surgery in patients with chronic limb-threatening ischemia

OBJECTIVE

Preoperative anemia in elderly patients undergoing surgery is prevalent and associated with adverse events; however, the interaction with other risk factors in patients with chronic limb-threatening ischemia (CLTI) is not well described. The purpose of this study was to assess the association between lower hematocrit (HCT) levels on admission and postoperative outcomes after infrainguinal bypass surgery.

METHODS

Patients with CLTI undergoing nonemergent infrainguinal bypass were identified in the targeted vascular module of National Surgical Quality Improvement Program (NSQIP; 2011-2014). The 30-day outcomes were compared across preoperative HCT levels: severe (≤29%), moderate (29.1%-34%), mild (34.1%-39%), or no anemia (>39%), with no anemia serving as the reference group for all analyses. Independent associations between levels of anemia and postoperative outcomes were established using multivariable logistic regression. A sensitivity analysis was performed to assess interactions between preoperative anemia and blood transfusions.

RESULTS

We identified 5081 patients undergoing bypass, of which 741 (15%) had severe, 1317 (26%) moderate, 1516 (30%) mild, and 1507 (30%) no anemia. Anemic patients were older and more commonly suffered from tissue loss and comorbidities (eg, hypertension, diabetes, and renal insufficiency; all P < .001). After adjustment for baseline conditions, mortality was higher in those with severe anemia (3.1%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.3-6.3) and moderate anemia (3.0%; OR, 2.6; 95% CI, 1.2-5.5) compared with those without anemia (0.7%). Severe anemia was independently associated with major amputation (6.9% vs 3.3%; OR, 1.6; 95% CI, 1.01-2.6) compared with no anemia. Anemia on admission was additionally associated with several other adverse outcomes, such as major adverse cardiovascular event (MACE; severe: OR, 1.9; 95% CI, 1.1-3.0; moderate: OR, 1.9; 95% CI, 1.3-2.9; mild: OR, 1.6; 95% CI, 1.1-2.4) and unplanned return to the operating room (severe: OR, 1.6; 95% CI, 1.2-2.1; moderate: OR, 1.5; 95% CI, 1.2-1.8; mild, OR: 1.3; 95% CI, 1.03-1.6). Moreover, mortality associated with preoperative anemia was not different in patients receiving postoperative blood transfusions compared with those who did not, whereas MACE was significantly higher in patients with preoperative anemia and blood transfusions (interaction; P < .001).

CONCLUSIONS

Mortality and major adverse events in CLTI patients undergoing infrainguinal bypass are inversely associated with preoperative HCT levels, with the highest event rates in the most severely anemic patients. The correlation between anemia and MACE-but not mortality-was stronger in those patients receiving postoperative blood transfusions. Further research is needed to define an appropriate transfusion threshold, and attention should be focused on how to best optimize anemic CLTI patients before intervention.

Postoperative acute kidney injury

Acute kidney injury (AKI) after cardiac surgery is a common and serious complication. Several definitions of AKI have been proposed recently, and include both increases in serum creatinine levels and decreases in urine output as diagnostic criteria. The pathophysiology of postoperative AKI is complex and involves both ischemic injury and systemic inflammation. Identifying risk factors, such as old age, underlying diabetes, heart failure, and obesity, may aid in the application of preventative methods for postoperative AKI. Additionally, recognizing different risks after different types of surgical procedures would be valuable. Novel biomarkers that could detect AKI more precisely at an earlier time point are being investigated. Several new biomarkers have been assessed in large multi-center studies and are believed to accommodate conventional clinical findings in diagnosing postoperative AKI. In high-risk patients, preventative measures, such as the maintenance of adequate hemodynamics and sufficient fluid resuscitation, could lower the incidence of postoperative AKI. Avoiding nephrotoxic agents and optimizing preoperative hemoglobin levels to avoid excessive transfusions would also be beneficial. In situations in which medical management fails to maintain sufficient urine output and acid-base and electrolyte homeostasis, early initiation of renal replacement therapy should be considered.

Pre-operative predictors of poor outcomes in patients undergoing surgical lower extremity revascularisation - Retrospective cohort study

BACKGROUND

Surgical lower extremity revascularisation (LER) can lead to poor outcomes that include delayed hospital discharge, in-hospital mortality, major amputations and readmissions. The aim of this study was to identify pre-operative predictors associated with these poor clinical outcomes.

MATERIALS AND METHODS

All patients (n = 635; mean age 69; male 67.4%) who underwent surgical LER over a 5 year period in a single tertiary vascular institution were identified. Patients considered to have suffered a poor outcome (Group A) included all in-hospital mortality and major amputations, delayed discharges with a length of stay (LOS) over one standard deviation above the mean or any readmission under any specialty within 12 months. Group A included 247 patients (38.9%) and the good outcome group included the remaining 388 patients (61.1%) from which a sample of 99 patients were selected as controls (Group B).

RESULTS

Mean LOS for the entire study group was 14.4 ± 17.5 days, 12 month readmission rate was 29.1% and in-hospital mortality and major amputation rate was 2.7% and 1.4%, respectively. Pre-admission residence other than own home (OR 9.0; 95% CI 1.2-70.1; P = 0.036), atherosclerotic disease burden (OR 2.2; 95% CI 1.3-3.8; P = 0.003) and tissue loss (OR 3.0; 95% CI 1.6-5.3; P < 0.001) were identified as independent, statistically significant pre-operative predictors of poor outcome. Following discharge, group B patients had a significantly higher rate of amputation free survival and graft infection free survival (P < 0.001) compared to group A.

CONCLUSION

Recognition of pre-operative predictors of poor outcome should inform case selection and identify high risk patients requiring intensive perioperative optimisation and post discharge follow up.

Perioperative clopidogrel is associated with increased bleeding and blood transfusion at the time of lower extremity bypass

OBJECTIVE

Controversy persists surrounding the perceived bleeding risk associated with perioperative clopidogrel use in patients undergoing lower extremity bypass (LEB). The purpose of this study was to examine the LEB bleeding risk and clinical sequelae associated with clopidogrel.

METHODS

All LEBs in the Vascular Quality Initiative (VQI) from 2008 to 2014 were studied. The exposure was perioperative clopidogrel. Primary outcomes were blood transfusion, estimated blood loss ≥500 mL, and reoperation for bleeding. Secondary outcomes included mean operative time, major cardiac events, respiratory complications, infectious complications, and in-hospital mortality. Univariate and multivariable analyses were used to analyze patients on the basis of clopidogrel use and its association with outcomes. Nonparametric test for trend and Mantel-Haenszel methods were used to analyze association of clopidogrel use with blood transfusion and secondary outcomes.

RESULTS

Among the LEB cohort (N = 9179), 28% (n = 2544) were taking clopidogrel and 72% (n = 6635) were not. Patients taking clopidogrel were more likely to have coronary disease, prior coronary intervention, abnormal findings on stress test, and aspirin use (P < .001 for all). Patients taking clopidogrel were more likely to receive blood transfusion (38% vs 24%; P < .001) and to have estimated blood loss ≥500 mL (21% vs 12%; P < .001). Reoperation for bleeding rates were similar (0.9% vs 1.1%; P = .9). Clopidogrel use was also associated with increased mean operative times (244 minutes vs 232 minutes; P < .001) as well as with cardiac complications (8.8% vs 6.5%; P = .001), respiratory complications (2.5% vs 1.6%; P = .007), and in-hospital mortality (1.3% vs 0.8%; P = .03). Multivariable analysis demonstrated that clopidogrel was associated with increased risk of 1- or 2-unit blood transfusion (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.5-2.1; P < .001) and >2-unit blood transfusion (OR, 2.0; 95% CI, 1.7-2.5; P < .001). Major cardiac events (OR, 1.2; 95% CI, 1.0-1.5; P = .05) and respiratory complications (OR, 1.4; 95% CI, 1.0-2.0; P = .03) were also independently associated with clopidogrel use. Weighted Mantel-Haenszel ORs controlling for blood transfusion amount revealed no remaining effect of clopidogrel on major cardiac events (OR, 1.1; P = .4) or respiratory complications (OR, 1.0; P = .8).

CONCLUSIONS

Perioperative clopidogrel use in LEB surgery is associated with increased blood loss and blood transfusion. Associated clinical sequelae include increased cardiac and pulmonary complications. Accordingly, surgeons should consider discontinuation of perioperative clopidogrel when it is clinically appropriate unless it is strongly indicated at the time of LEB.

Stratification and Risk Reduction of Perioperative Acute Kidney Injury

Perioperative acute kidney injury (AKI) is associated with an increased morbidity and mortality. The incidence of AKI varies depending on preoperative risk factors and the surgical setting. Preoperative risk stratification is critical for informed consent and perioperative planning. Perioperative renal protection strategies are potentially invaluable in the prevention of AKI. Current advances in the development of biomarkers may offer the opportunity for early diagnosis and the implementation of therapeutic strategies. Increased awareness and concerted efforts by all perioperative physicians are needed to provide an improved outcome for surgical patients.

Significant regional variation exists in morbidity and mortality after repair of abdominal aortic aneurysm

OBJECTIVE

Limited data exist comparing perioperative morbidity and mortality after open and endovascular abdominal aortic aneurysm (AAA) repair (EVAR) among regions of the United States. This study evaluated the regional variation in mortality and perioperative outcomes after repair of AAAs.

METHODS

The Vascular Quality Initiative (VQI) was used to identify patients undergoing open AAA repair and EVAR between 2009 and 2014. Ruptured and intact aneurysms were evaluated separately, and the analysis of intact aneurysms was limited to infrarenal AAAs. All 16 regions of the VQI were deidentified, and those with <100 open repairs were combined to eliminate the effect of low-volume regions. Regional variation was evaluated using χ² and Fisher exact tests. Regional rates were compared against current quality benchmarks.

RESULTS

Perioperative outcomes from 14 regions were compared. After open repair of intact aneurysms, no significant variation was seen in 30-day or in-hospital mortality; however, multiple regions exceeded the Society for Vascular Surgery benchmark for in-hospital mortality after open repair of intact aneurysms of <5% (range, 0%-7%; P = .55). After EVAR, all regions met the Society for Vascular Surgery benchmark of <3% (range, 0%-1%; P = .75). Significant variation in in-hospital mortality existed after open (14%-63%; P = .03) and endovascular (3%-32%; P = .03) repair of ruptured aneurysms across the VQI regional groups. After repair of intact aneurysms, wide variation was seen in prolonged length of stay (>7 days for open repair: 32%-53%, P = .54; >2 days for EVAR: 16-43%, P < .01), transfusion (open: 10%-35%, P < .01; EVAR: 7%-18%, P < .01), use of vasopressors (open: 19%-37%, P < .01; EVAR: 3%-7%, P < .01), and postoperative myocardial infarction (open: 0%-13%, P < .01; EVAR: 0%-3%, P < .01). After open repair, worsening renal function (6%-18%; P = .04) and respiratory complications (6%-20%; P = .20) were variable across regions. The frequency of endoleak at completion of EVAR also had considerable variation (15%-38%; P < .01).

CONCLUSIONS

Despite limited variation, multiple regions do not meet current benchmarks for in-hospital mortality after open AAA repair for intact aneurysms. Significant regional variation exists in perioperative outcomes and length of stay, and mortality is widely variable after repair for rupture. These data identify important areas for quality improvement initiatives and clinical practice guidelines.

Risk stratification for the development of respiratory adverse events following vascular surgery using the Society of Vascular Surgery's Vascular Quality Initiative

OBJECTIVE

Postoperative respiratory adverse events (RAEs) are associated with high rates of morbidity and mortality in general surgery, however, little is known about these complications in the vascular surgery population, a frail subset with multiple comorbidities. The objective of this study was to describe the contemporary incidence of RAEs in vascular surgery patients, the risk factors for this complication, and the overall impact of RAEs on patient outcomes.

METHODS

The Vascular Quality Initiative was queried (2003-2014) for patients who underwent endovascular abdominal aortic repair, open abdominal aortic aneurysm repair, thoracic endovascular aortic repair, suprainguinal bypass, or infrainguinal bypass. A mixed-effects logistic regression model determined the independent risk factors for RAEs. Using a random 85% of the cohort, a risk prediction score for RAEs was created, and the score was validated using the remaining 15% of the cohort, comparing the predicted to the actual incidence of RAE and determining the area under the receiver operating characteristic curve. The independent risk of in-hospital mortality and discharge to a nursing facility associated with RAEs was determined using a mixed-effects logistic regression to control for baseline patient characteristics, operative variables, and other postoperative adverse events.

RESULTS

The cohort consisted of 52,562 patients, with a 5.4% incidence of RAEs. The highest rates of RAEs were seen in current smokers (6.1%), recent acute myocardial infarction (10.1%), symptomatic congestive heart failure (9.9%), chronic obstructive pulmonary disease requiring oxygen therapy (11.0%), urgent and emergent procedures (6.4% and 25.9%, respectively), open abdominal aortic aneurysm repairs (17.6%), in situ suprainguinal bypasses (9.68%), and thoracic endovascular aortic repairs (9.6%). The variables included in the risk prediction score were age, body mass index, smoking status, congestive heart failure severity, chronic obstructive pulmonary disease severity, degree of renal insufficiency, ambulatory status, transfer status, urgency, and operative type. The predicted compared with the actual RAE incidence were highly correlated, with a correlation coefficient of 0.943 (P < .0001) and a c-statistic = 0.818. RAEs had a significantly higher rates of in-hospital mortality (25.4% vs 1.2%; P < .0001; adjusted odds ratio, 5.85; P < .0001), and discharge to a nursing facility (57.8% vs 19.0%; P < .0001; adjusted odds ratio, 3.14; P < .0001).

CONCLUSIONS

RAEs are frequent and one of the strongest risk factors for in-hospital mortality and inability to be discharged home. Our risk prediction score accurately stratifies patients based on key demographics, comorbidities, presentation, and operative type that can be used to guide patient counseling, preoperative optimization, and postoperative management. Furthermore, it may be useful in developing quality benchmarks for RAE following major vascular surgery.

Point-of-care platelet function testing to predict blood loss after coronary artery bypass grafting surgery: a prospective observational pilot study

Aim:

With an increase in the number of patients who are on antiplatelet medications until the day of surgery, we undertook a prospective observational study to assess the ability of thromboelastography, thromboelastography platelet mapping and aggregometry via multiplate to detect platelet dysfunction and predict blood loss following coronary artery bypass grafting (CABG) surgery.

Methods:

Platelet function was evaluated pre- and post-cardiopulmonary bypass via thromboelastography, thromboelastography platelet mapping and aggregometry via multiplate in 52 patients undergoing coronary artery bypass grafting surgery. The median chest tube drainage of all patients in the study was ascertained to stratify patients into two groups: patients with and those without evidence of excessive blood loss after cardiac surgery.

Results:

Although all modalities could detect a decrease in platelet function following cardiopulmonary bypass, univariate and multivariate regression analysis identified preoperative arachidonic acid and adenosine diphosphate testing via multiplate as independent predictors of bleeding after cardiac surgery. Receiver operating curves on these multiplate parameters showed an area under the curve of 0.68 (p=0.03) and 0.66 (p=0.01) for arachidonic acid and adenosine diphosphate assays, respectively.

Conclusion:

This pilot study shows that preoperative multiplate testing may be a better predictor of platelet dysfunction and the resultant blood loss following cardiac surgery.

Causes of 30-day readmission after neurosurgery of the spine

OBJECT

Thirty-day readmission has been cited as an important indicator of the quality of care in several fields of medicine. The aim of this systematic review was to examine rate of readmission and factors relevant to readmission after neurosurgery of the spine.

METHODS

The authors carried out a systematic review using several databases, searches of cited reference lists, and a manual search of the JNS Publishing Group journals (Journal of Neurosurgery; Journal of Neurosurgery: Spine; Journal of Neurosurgery: Pediatrics; and Neurosurgical Focus), Neurosurgery, Acta Neurochirurgica, and Canadian Journal of Neurological Sciences. A quality review was performed using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) criteria and reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

A systematic review of 1136 records published between 1947 and 2014 revealed 31 potentially eligible studies, and 5 studies met inclusion criteria for content and quality. Readmission rates varied from 2.54% to 14.7%. Sequelae that could be traced back to complications that arose during neurosurgery of the spine were a prime reason for readmission after discharge. Increasing age, poor physical status, and comorbid illnesses were also important risk factors for 30-day readmission.

CONCLUSIONS

Readmission rates have predictable factors that can be addressed. Strategies to reduce readmission that relate to patient-centered factors, complication avoidance during neurosurgery, standardization with system-wide protocols, and moving toward a culture of nonpunitive system-wide error and “near miss” investigations and quality improvement are discussed.

Blood transfusion is associated with increased risk of perioperative complications and prolonged hospital duration of stay among patients undergoing amputation

OBJECTIVE

We evaluated the outcomes of patients undergoing major lower-extremity amputation who received packed red blood cell transfusion.

METHODS

Using the dataset of the National Surgical Quality Improvement Program (2005-2011), we examined 5,739 above-knee and 6,725 below-knee amputations. Patients were stratified by perioperative (preoperative, intraoperative, or postoperative) blood transfusion. Outcomes included perioperative mortality, myocardial infarction (MI), thromboembolism, and duration of stay (DOS) at the hospital. Adjusted comparisons of outcomes between transfused and not-transfused patients were performed by matching the 2 groups for age, smoking, diabetes, renal failure, coronary artery disease, classification of the American Society of Anesthesiologists, functional status, and procedure type. Multivariable logistic and gamma regression were used to examine associations between transfusion and outcomes.

RESULTS

Of the 12,464 amputations in the study cohort 2,133 (17%) required transfusion. The majority of the cases were performed for critical limb ischemia (8,205 amputations; 66%) and the overall 30-days mortality was 9%. In both crude and matched cohorts, although perioperative mortality and cardiac complication rates were similar, transfusion was associated with a greater incidence of pneumonia (crude: 6.1% vs 3%, P < .001; matched: 5.9% vs 3.7%, P < .001), thromboembolism (2.5% vs 1.6%, P = .003; 2.5% vs 1.4%, P = .002) and longer DOS (18 ± 19 vs 13.6 ± 14.3 days, P < .001; 17.8 ± 18.4 vs 14.2 ± 14.5 days, P < .001). Multivariable adjustment for confounding variables in the crude cohort demonstrated that transfusion was independently associated with a greater odds of perioperative pneumonia (odds ratio [OR]:1.6; 95% confidence interval [CI]:1.3-2; P < .001), thromboembolism (OR 1.3, 95% CI 1.0-1.9, P = .09) and longer DOS (mean ratio: 1.1; 95% CI 1.1-1.6; P = .006).

CONCLUSION

Among patients who had major lower-extremity amputation, perioperative transfusion independently predicted greater risks for perioperative pneumonia, thromboembolism, and prolonged hospital DOS.

Statewide Collaboration to Evaluate the Effects of Blood Loss and Transfusion on Surgical Site Infection after Hysterectomy

We used mandatory public reporting as an impetus to perform a statewide study to define risk factors for surgical site infection. Among women who underwent abdominal hysterectomy, blood transfusion was a significant risk factor for surgical site infection in patients who experienced blood loss of less than 500 mL.

Infect Control Hosp Epidemiol 2012;33(1):90-93